Load indicator



Sept. 6,1927. 1,641,296

' F.YL.. SCOTT LOAD INDICATOR Sept. 6, 1927. F' L SCOTT LOAD INDICATOR IFiled May 5, 1926 2 Sheets-Sheet 2 .l NTC Fly@ @Hoz new Patented Sep-t. 6, 1927.

UNITED STATES PATENT OFFICE.

FLOYD L. SCOTT, OF HOUSTON, TEXAS, ASSIGNOR TO HUGHES TOOL COMPANY, OF

HOUSTON, TEXAS, A CORPORATION 0F TEXAS.

Loan INDICATOR.

Application med may s, 192s. serial No. 106,574.

My invention relates to a means to measure the changes in the amount of load placed upon a structure. It is particularly designed for use in well drilling operations to indicate the load allowed to bear upon the drill at thebottomV of they well. It is an object of my invention to use a portion of the load supporting derrick. employed indrilli'ng to show, by its compression under the load, the relative changes in of adjusting 'nuts 5, 5 oneach side of said In drilling with the rotary drill, and espethe weight supported by the saidderrick.

cially with a rotary drill of the roller type, it is particularly desirable to place upon the bit during this drilling operation a certain predetermined load which shall not beexcessive. Drills now ordinarily employed will work with maximum efficiency when the load resting upon the tools is not too great. The weight of the drill stem by means of which the drill is operated is at ordinary depths too great,.and it becomes necessary to sup port a large part of the weight ,upon the calle suspended at the upper end of the derric l I have found that one of the best indications of the load supported by the derrick is found in the degree of compression upon the frame of the derrick itself under lthe weight.- I therefore contemplate securing an indicating means between two points upon the side of thederrick and to note the compression of the derrick under the load by an indicating dial at one of the selected points.

Referring to the drawing herewith wherein a preferred embodiment-of my invention' is disclosed, Fig. 1 is a vertical longitudinal section through a portion of the derrick frame and through the housing of the indicating device, Fig. 2 is a top plan view of the indicating device, Fig. 3 is a front elevation thereof, andFig. 4 is a front elevation of the indicating device showing the same connected by means of a wire to an upper bracket on the derrick frame. Like numerals of reference are employed to designate like p arts in all the views. A

Referring to Fig. 4, I have shown one leg of the derrick l1, which is preferably made up of a plurality of planks. of the desired width nailed together at one edge as shown in Fig. 2 so asto make a' substantial upright support. A derrick leg thus formed provides an inner rlghtl angular recess 1n Ithe u per end of the cu which to support the indicating device. At a polnt spaced upwardly from the floor of the derrick I place a bracket 2 which fits with the angleof the derrick le'gand is secured to' the planks formingthe same4 by screws or otherwiseto form a rigid Connection therewith.' T lie bracket has a forwardly extending arm 3 with an' opening therein to receive a screw which maybe ad]usted vertlcally in said opening by means arm. f

Spaed downwardly from the upper bracket upon the derrick leg and at a polnt close enough to the derrick platform tovbe easily inspected by the drilling operator, I place an. indicating device shown at 6. The

construction of the indicator is shown best in Fig. 1. -It is :formed of a bracket7 formed to fit within 'the an le of the derrick legv and secured thereto at t e upper and lower ends by means of lag screws 8. Upon this bracket are secured upper and lower spring arms 9 and 10 respectlvely. These arms, as shown in dotted lines in Fig. 2, are wider at their inner ends adjacent the derrick leg, and are tapered outwardly, and have the outer .end

recessed slightly, to, fit about a `push rod. The upper spring arm 9 has a central opening therethrough to receive a threaded end v11 of `the upper -section of the push rod4 12.

Said up er section of the push rod is provided with an eyelet'13 to receive a wire 14:l

by means of which the said push rod is con nected with the adjusting upper bracket'. The lower spring 10`receives adapted to work within a cup or cylinder 18' thus forming. a dash pot. The cylinder 18 is threaded at its upper end at 19 for enscrewl Ltof the. f

'the lower end of the pushrod 12and is-fitted between a bearing member 15 and a lock nut l gagement with,l a. downwardly extending annular flange 20 upon the housing 21. plurality of openings 22 are formed adjacent to provide for the over ow of oil or-other uid used in connection with -the dash pot arrangement. A threaded plug 23 closes an opening in `the upper end of the dash pot housing to allow the refilling of the dash pot with oil or other liquid 'when necessary. A skirt 24 is exy 10 as a support and partly to protect the working parts of the weight indicator. On the Vup er `face'of the housin adjacent the push ro the wall ofthe houslng is extended upwardlyat 25,4 and the push rod working 1'5 through the. opening adjacent thereto 'has thereon a cap or Ilan e 26 which lits around the flange upon the ousing thus serving to protect the interior -of the housing from mud or dirt. d

Secured to the forward aceof thehousing ad'acent the ,push rod is the dial 'of the indicating apparatus. This dial has a central, rotatable shaft or pin 2f? thereon upon fwhich is lixed a hand or pointer 28. Im-

25. mediately back'of the said pointer is a graduated scale 29 of the usual form used with weight indicating devices. The shaft 27 upon-'which' the pointer is fixed has thereon a small gear meshing with a rack upon a 30 shaft 30. This construction'is common in indicating devices and is not shown in detail.

. The lower end of the shaft 30 projects through the housing of the indicator, and

' bears against'the upper 'ace of the bearing 35- member 15 upon vthe ush rod las shown par- 4 ticularl .in Fig. 1. he shaft is held resiliently dbwnward against the bearing member by any ordinary construction not shown;

Adjacent the 'shaft27 on the face lof the j ecwdial` is ,a small pointer 3l working on 'a smaller dial face, and acting to indicate the lthe l larger hand 'number of revolutions of upon thev dial 29. Y c

. In'order to set the hand or pointer 28 at 15 zero uponJ the dial it is necessary to provide an adjusting mechanism which lconsists of a central spring arm`32 secured by screws 33 to the housing, approximately midway bel tween the two spring arms 9 and 10. The

said arm has a notch in the outer end straddling the push rod, and has secured at-itsv xfonwa'rdend a bar 34 secured to the rear-side l of the housing :l5/of the indicating mchaf Below the bar 34 is a transverse l U shaft'journalledv at its ends in the housing'21'and having-.thereon an eccentric por-A tion 37 vacting as a cam, the rotationl of 'which wilma@ or lower'ule bar s4 and with it the housing 85. A handle 40,011 said 004 shaft serves to rotate it. This will serve to o adjust the pointer 28 in an obvious manner. In the operation of my device'theindi-- V vcater is secured at the: roper elevation upon the leg of the derric and the bracket 2 is securedl in .properly spaced relation at a point approximately vertically above the indicator, andthe tension upon the connect ing rod or wire 14 is adjusted by means of .the nuts 5, 5. By thus adjusting the tension vupon wire 14, the pointer may be brought approximately to zero upon 'the' dial. Further adjusting fortaccuracy may'- be made through` thecam 37 raising or lowering the housing relative to the bearing memberl upon `which the shaft 30 rests. 75 The connecting rod or wire 14 is preferably made of a metal having approximately the; same coefficient of expansion under heat as has the wooden frame of the derrick, thus avoiding any deterimental effect upon the accurate operation of the device through the unequal expansion of the frame relative to the connecting rod. -I have found that an alloy of nickel and iron will have the correct vcoeliicient ofexpansion.

vWhen the load is placed upon the derrick by hoisting the drill stem and bit oli' the bot-4 tom of the well, the hand 28 of the indicator may be reset to stand at zero. The drill then lowered upon the bottom of the hole 90 until the correct amount of weight rests thereon. This is determined by the driller largely from experience, and it may be that ,Qn the installation employed by him the pointer will stand atI Supon the dial. Tf this is taken as the oint upon the dial where the hands shoul be allowed to stand, it will be easy for the driller thereafter to retain the proper weight upon the drill to maintain the pointer at this gure. A greater or less weight upon the drill will cause the 4pointer to move from the correct place upon the dial. f

The dash pot employedv by the push rod will lar ely overcome the tendency of the push rod to vibrate rapidly from the eflects `of the drill.- The ordinary roller drill as hinge support such as'wouldv ordinaril 4tend to aiect the free operation of the pus rod, 120 and the tendency of the supporting arms is to hold th'eplush rod in the position at which itis set.A e complete installation is light and compact in orm,and may be easilyand quicklyinstalled upon any derrick of odinary construction. It employs but a short length of the derrick (from twenty to thirty feet thereof), and the compression caused by the load upon the derrick leg is found to be suilicient to indicate with great accuracy 13 operatingin rock will have a strong'vibrafw Y ported upon the load will be easil l upon .to show the exact weight ynote the point indicated upon stem,

the variations in the load sustained by the derrick; I

It is not desired in this indicating device in pounds resting on the drill. It is simply intended to show variations in the load resting onfthe drill, and ity will be necessary for the driller to the dial when the desired weight rests upon the drill, and to maintain thereafterv the pointer at this mark. Ifthe load increases due to theaddition of further lengths of pipe or drill the pointer may be quick y setto zero as previously described by turning the hand to the zero point while the entire load is supderrick. If the load is then allowed to rest upon the drill until the hand reaches the desired ypoint upon dthe dial,the maintaine .at the required amount. I it reviously indicated 3 the dial, if it is rought to that point each time, it will show thedesired load uponv the drill.

Having thu described myinvention, the further objects and advantages vof which will be apparent to one skilled in the art,

i what 'I claim as new and desire to protect by Letters Patent, is:

1. A load indicator for well drilling operations, 'comprising a load supporting derrick leg, an indicating'vdevice secured rlgidly at a desired point on said derrick leg, a

adjacent said indicator, an oper bracket secured on said leg at a point spaced from said indicating device, a push rod,

means for resiliently supporting said rod.

Von said device, a tension wire connecting said push rod and said bracket and a pointer actuated by said push rod to'show. variations iln the load acting to compress said derrick A load indicator for well ydrillin 4comprising a load sup orting lderrick gleg, a bracket secured rigi thereto, an indicator secured rigidly to sai le at a point spaced from said bracket, a'dia on said indicator, a pointer on said dial, a push rod, means for resiliently sup rti'ng said rod on said le ting sha ing dial, a pointer, a s

`supported rigidly on for said pointer bearing. on said push rod and a tension wire connecting said push rod and said bracket. 3. A load indicator for well drilling comprising a derrick leg, a bracket thereon, an in' dicator housin from said brac. et, a rotating pointer on sald indicator, an operating shaft for said pointer, a push rod. means for resiliently supporting said rod in said housing and bearing against said shaft, a tension wire between said` push r'od and bracket, and means lto dampen the 'movement of said rod. 4. A load indicator for well drilling rigs comprising a derrick frame, an indlcator support on said frame, a push rod slidable verticall in said support, a pointer operating sha t movable through lmeans of said push rod, resilient' supporting' means -for said rod, a bracket on said frame spaced vertically from said indicator, and a taut wire connecting said push rod and said bracket for the purpose described. l A5. A 'load .indicator for well drillingl rigs comprising a derrick frame, an indicator support secured rigidl thereto, an indicathaft insaid indicator support adapted to move. said ointer relative to the dial, a push rod slldable vertically in said housing Jand bearing on saidv shaft, resilient plates supporting said push rod; a bracket spaced vertically from said' support, and means connecting said push rod i and bracket whereby compression of said frame vwill move said push rod andsaid shaft.'

6. In ay rigs, a derrick leg,

load indicator for well drilling a weight indicating'scale said leg, ain attaching means `spaced vertically from said scale on said leg, and a rigid connecting means between the said scale and said attachin means, whereby compression of said derric le will actuate said weight indicating scale.

n testimony whereof, I hereunto ai'nx my l signature, this the 28th day of April, A. D. 1926.

FLOYD n soo'r'r( 

